The M127 is a versatile shotgun in regard to the wide array of shotshells it can run. However, with that being said, it has an initial break-in period to achieve 100% reliability. Break-in would be summed up as when the parts clearance themselves through repeated cycling and the springs take a set to their working height. You have probably noticed a bronze-colored grease on some firearms which is an anti-seize compound so that the firearm doesn’t weld itself together while breaking in. However, we use a heavy gun grease such as Lucas. As of this writing, ammunition has become hard to obtain. That will dictate on how to get the gun up to speed. On the low end of the power spectrum, it is best to steer clear of any loads that are less than 1 ⅛ ounce and velocities below 1200 fps. Use the yellow recoil spring if you are shooting the lower power ammo. It will be more than sufficient to handle even lower recoil 00 buck. When we test fire, we apply a heavy amount of gun grease to the bolt carrier, charging handle, and the hammer face. This helps with the lapping in of the moving parts. It is a good idea to keep it heavily lubed during the first 100-200 rounds. After the gun starts to loosen up, you can back off on the lube. We have guns that have thousands of rounds through them, and they run reliability with minimal cleaning and lube. On a side note, there is no one size fits all. If you feel excessive recoil, go to the next hotter recoil spring. We will go into more detail about spring selection in another post. Happy shooting!